This invention relates to automatic car washing apparatus, and to brush assemblies therefor. As used herein, the term "car" refers to automobiles, vans, panel trucks, light trucks, and similar vehicles.
Automatic car washing apparatus commonly include several spaced apart rotatable brushes between which the car is advanced, usually by means of a chain conveyor, and guided by a wheel track which engages the wheels of one side of the car, for example, the driver or left side. The brushes are located adjacent a washing station at which the surfaces of the car are wetted by water and a cleaning agent. To clean the top of the car, a top brush is rotatably supported for rotational movement about a horizontal axis by arms which are pivotally mounted above the washing station to swing the top brush into and out of engagement with the upper surface of the car. To clean the sides and ends of the car, one or more side brushes are rotatably supported for rotational movement about vertical axes by arms which are pivotally mounted adjacent the sides of the washing station to swing the side brush or brushes horizontally into and out of engagement with first the front end surface of the car, then the sides and rocker panels, and finally the rear end surface of the car, as the car is advanced through the washing station. To ensure proper cleaning of the side and end surfaces of the car, conventional car wash apparatus merely position a series of brushes at spaced apart locations along the washing station, each brush being operated to clean a specific surface. Consequently, such apparatus tend to be extremely long in order to accommodate all these brushes and it is often difficult to provide and maintain adequate brush position control and contact pressure. See, for example, U.S. Pat. No. 3,332,098, issued to Smith.
To increase cleaning efficiency with minimum complexity, therefore, it is desirable to utilize a single side brush assembly to clean several car surfaces. Typically two commonly pivoted brushes are employed in this type of side brush assembly--one to clean the front and side, the other to clean the side and rear surfaces of the car--as disclosed in U.S. Pat. No. 3,327,229 to Weigele, et al. and U.S. Pat. No. 3,688,328 to Wilkins. To provide car wash apparatus for cleaning both sides and ends of the car, two such side brush assemblies are employed. Inasmuch as the brushes of each side brush assembly are resiliently interconnected, however, these prior side brush assemblies cannot adequately wash cars of varying widths. The driver or left side brush assembly operates properly regardless of car width because that side of the car is positioned, with respect to the left side brush assembly, by the wheel track; however, the relative positions of the passenger or right side brush assembly and the right side and end car surfaces can vary, depending upon the width of the car, such that the right side brushes prematurely snap back from, completely miss, or exert insufficient cleaning pressure upon the right side and rear end surfaces of the car. The end result is that only cars of standard width, which can be drawn through the washing station such that the car and washing apparatus centerlines substantially coincide, receive a thorough and complete cleaning. Another problem associated with such operation of the right side brushes is that brush penetration and contact pressure applied can vary, or the cleaning work load is distributed unevenly among the four side brushes, depending upon the width of the car, with resultant decreased brush life, and hence increased operating cost. Further, due to the conjoint movement of the brushes produced by resiliently interconnecting them, it is necessary, in order to prevent opposite brushes from clashing with one another at their cleaning positions, to stagger opposite brush assemblies along the path of car advance. Consequently, as is the case with multiple brush conventional car wash apparatus described previously, the resulting apparatus is of undesirable length and complexity.